Modeling MRI contrast enhancement with exogenous T2 agents

Superparamagnetic contrast agents are a widely studied for emerging cellular-molecular applications. Rational development of new generations of agents requires a computational scheme for predicting contrast enhancement in vivo. A general theoretical model is presented to evaluate the minimal concentration of a T2 contrast agent providing satisfactory MRI contrast. The model requires only a few key parameters that are readily evaluated. The model is applicable to a wide range of T2 agents and delivery scenarios. We apply the model to Feridex, a commercial agent, and ferritin, an iron storage protein that can be used as a novel intracellular contrast agent.